feat(02-02): JournalEntry models + JournalEntryService

- Add JournalEntryStatus and JournalEntrySource enums to Prisma schema
- Add JournalEntry model with maker-checker fields, self-referential reversal relation, and audit timestamps
- Add JournalEntryLine model with debit/credit Decimal(15,2) fields
- Update Account model with journalEntryLines back-relation
- Update User model with createdJournalEntries and approvedJournalEntries back-relations
- Run migration: 20260304150817_add_journal_entry_models
- Add journalEntry and journalEntryLine to TENANT_SCOPED_MODELS in prisma-tenant.ts
- Create JournalEntryService with createEntry, approveEntry, reverseEntry, getAccountBalance, getTrialBalance
- Enforce debit=credit balance using integer cents comparison (avoids float issues)
- SYSTEM source entries auto-posted; MANUAL entries start as DRAFT for maker-checker

src/lib/prisma-tenant.ts

@@ -30,7 +30,7 @@ import { prisma } from "@/lib/prisma";
  * Extend this list as new models are added in later phases:
  * e.g., "subscriber", "invoice", "servicePlan", "payment"
  */
-export const TENANT_SCOPED_MODELS = ["user", "account", "accountingPeriod", "subscriber", "servicePlan", "tenantSettings"] as const;
+export const TENANT_SCOPED_MODELS = ["user", "account", "accountingPeriod", "subscriber", "servicePlan", "tenantSettings", "journalEntry", "journalEntryLine"] as const;
 
 export type TenantScopedModel = (typeof TENANT_SCOPED_MODELS)[number];
 
@@ -608,6 +608,134 @@ export function withTenantContext(tenantId: string) {
           return query(args);
         },
       },
+
+      journalEntry: {
+        async findMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirst({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirstOrThrow({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findUnique({ args, query }) {
+          if (args.where && "id" in args.where && !("tenantId" in (args.where as object))) {
+            return prisma.journalEntry.findFirst({
+              ...args,
+              where: { ...args.where, tenantId },
+            });
+          }
+          return query(args);
+        },
+
+        async findUniqueOrThrow({ args, query }) {
+          if (args.where && "id" in args.where && !("tenantId" in (args.where as object))) {
+            const result = await prisma.journalEntry.findFirst({
+              ...args,
+              where: { ...args.where, tenantId },
+            });
+            if (!result) {
+              throw new Error("Record not found");
+            }
+            return result;
+          }
+          return query(args);
+        },
+
+        async create({ args, query }) {
+          args.data = { ...args.data, tenantId } as typeof args.data;
+          return query(args);
+        },
+
+        async update({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async updateMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async delete({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async deleteMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async count({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async aggregate({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async groupBy({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+      },
+
+      journalEntryLine: {
+        async findMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirst({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirstOrThrow({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findUnique({ args, query }) {
+          if (args.where && "id" in args.where && !("tenantId" in (args.where as object))) {
+            return prisma.journalEntryLine.findFirst({
+              ...args,
+              where: { ...args.where, tenantId },
+            });
+          }
+          return query(args);
+        },
+
+        async create({ args, query }) {
+          args.data = { ...args.data, tenantId } as typeof args.data;
+          return query(args);
+        },
+
+        async count({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async aggregate({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async groupBy({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+      },
     },
   });
 }